Universal mechanical seal gland

ABSTRACT

A universal mechanical seal gland formed of plastic has a central aperture positionable over a shaft extending from a housing for positioning a stationary seal against a rotary seal on the shaft. The central aperture is formed of a plurality of cylindrical and radial surfaces which define sealing surfaces permitting the gland to be used with a variety of differently sized and shaped seal members and housings and differently sized shafts.

BACKGROUND OF THE INVENTION

This invention is in the field of rotary shaft seals and is moreparticularly directed to a seal gland capable of usage with a variety ofrotary mechanical shaft seals of different sizes and shapes.

A wide variety of devices such as pumps, compressors and the like employrotary shafts supported for rotation in a housing in which pressurizedliquid engages the shaft on the interior of the housing and tends toleak outwardly along the shaft to the exterior of the housing. Suchleakage is obviously undesirable for a variety of reasons such asenvironmental contamination where the liquid is a hazardous chemical,cost of the lost liquid, cleanup costs and maintenance costs and theloss of energy resulting from such leakage. A common and well-knownexpedient for reducing leakage around a shaft is that of providing astuffing box surrounding the shaft with packed stuffing material beingheld in contact with the shaft. Improvements over the stuffing boxconcept have included rotary mechanical seals which basically consist ofan annular rotary seal member fixed to the shaft for rotation therewithand having a radial surface engageable with a radial surface of a fixedannular seal member held in position against the rotary seal by a glandmember machined to provide the necessary geometry and spacing foreffecting a satisfactory contact between the contacting radial surfacesof the rotary annular seal member and the fixed annular seal member.Such a conventional gland construction is illustrated by element 36 inFIG. 2 of the prior Peet U.S. Pat. No. 3,961,799. Additionally, the Peetpatent also illustrates other differently shaped gland members 26₁, 26₂,and 26₃, all of which share in common the fact that they can only beused with a rotary shaft of a given diameter and are not usable in otherdevices having shafts of different diameters. While the devicesillustrated in the Peet patent represent an advancement over the priorart, they suffer from the disadvantage that they consume a substantialamount of space axially along the length of the shaft with which theyare associated by virtue of the fact that the sealing system disclosedin the Peet patent necessarily requires an adapter ring 46 or 94 whichnecessarily increases the axial length of the space in which the sealingcomponents must be located. Thus, not only is the system of the Peetpatent incapable of using the same gland for different sizes of shafts,it also suffers from the disadvantage of requiring a substantial amountof axial space along the length of the shaft and is therefore unusablewith apparatus in which such space is not available. Thus, an essentialrequirement of the Peet system is the employment of the adapter rings46, 94 for positioning between the gland member and a specially designeduniversal fixed sealing member such as members 44, 44', 80 and 98 asillustrated in the Peet patent. The present universal gland memberinvention avoids the need for using such specially designed sealmembers, eliminates the need for adapter rings and also permits theusage of the universal gland member with a wide variety of mechanicalseal constructions and different shaft sizes.

SUMMARY OF THE INVENTION

Therefore, it is a primary object of the present invention to provide anew and improved mechanical seal gland.

The further object of the present invention is the provision of a newand improved mechanical seal gland capable of usage with a wide varietyof mechanical seal constructions, different shaft sizes and differentgland bolting configurations.

Achievement of the foregoing objects is permitted by the preferredembodiment of the present invention through the provision of amechanical seal gland comprising a polypropylene body having an axiallyextending aperture extending between parallel front and rear planarsurfaces with the axially extending aperture being defined by aplurality of cylindrical surfaces connected by radial surfaces with thecylindrical surfaces being of different diameters. The smallest diametercylindrical surface is centrally positioned midway between the front andrear surfaces of the polypropylene block with adjacent cylindricalsurfaces respectively being provided between the smaller diametersurface and the front and rear surfaces. The cylindrical surfaces inconjunction with their adjacent radial surfaces define step annular sealengaging surfaces which engage an annular stationary seal member formedof ceramic material or the like for holding the seal member in contactwith a shaft-mounted rotary seal component of a mechanical sealcombination. The plurality of such annular surfaces on the gland permitits usage with a wide variety of fixed stationary seal members as occurwith different sizes of shafts with the only limitation being that thediameter of the shaft must be less than the diameter of the centrallypositioned smallest diameter cylindrical surface of the gland.

The gland member is provided with a plurality of concentric circlesformed in its front surface for providing a guide for permittingmounting apertures to be bored at desired radial distances from thecenter of the gland for permitting connection of the gland to tappedopenings in a particular pump or compressor housing. Additionally, thegland body can be provided with inwardly extending bolt-receiving slotswhich extend inwardly from the cylindrical periphery of the gland or itcan be provided with pre-bored mounting bolt receiving holes if desired.Another variation of the gland resides in the provision of chordalsurfaces forming a portion of the outer periphery of the gland so as topermit it to be fitted onto housings having space limitations whichwould not accommodate a gland having a cylindrical outer periphery ofthe same diameter as the diameter of the cylindrical portions of thegland.

A better understanding of the contruction and usage of the preferredembodiments of the present invention will be achieved when the followingdetailed description is considered in conjunction with the appendeddrawings in which like reference numerals are used for the same parts inthe different views.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation view of the preferred embodiment;

FIG. 2 is an exploded perspective view of the preferred embodiment shownin association with a typical conventional rotary and fixed sealcomponent of a mechanical seal;

FIG. 3 is a bisecting sectional view of a portion of a housing, shaftand mechanical seal means with which the preferred embodiment isassociated;

FIG. 4 is a sectional view similar to FIG. 3 but illustrating theuniversal gland with a second type seal used in conjunction with asecond shaft size;

FIG. 5 is a sectional view similar to FIGS. 3 and 4 but illustrating theuniversal gland in use with a third type seal and a third shaft size;

FIG. 6 is a sectional view similar to FIGS. 3-5, but illustrating asecond embodiment of the universal gland in use with a sealing memberrequiring a peripheral seal connection;

FIG. 7 is a sectional view similar to FIG. 6 illustrating the secondembodiment of the universal gland in use with the different type ofperipheral seal; and

FIG. 8 is a front elevation view of a third embodiment of universalgland.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Attention is initially invited to FIGS. 1-3 of the drawings whichillustrate the preferred embodiment of the universal gland, generallydesignated 10, which comprises a solid body formed of polypropylenehaving a cylindrical peripheral surface 12 and a front generally planarface surface 14 and a generally planar rear face surface 16. Thegenerally planar front face surface 14 is provided with a plurality ofinscribed concentric bolt hole circles 18 which are concentric to a mainaxis 20. Concentric bolt hole circles 18 permit the location of bolthole centers 22 at desired diameters for a particular installation as isrequired by the housing in which mounting bolts for the gland are to bemounted. FIG. 1 merely illustrates the bolt hole openings in phantomlines; however, FIGS. 2 and 3 illustrate the condition of the glandfollowing the boring of bolt holes 24 preparatory to installation of thegland on a particular housing 26 as shown in FIG. 3.

The universal gland 10 is provided with a central aperture extendingbetween the front base surface 14 and rear face surface 16 which isdefined by a plurality of concentric cylindrical surfaces of differentdiameter which are connected by radial surfaces. More specifically, acentral cylindrical surface 30 is provided at a medial location midwaybetween the front and rear face surfaces 14 and 16 and is connected by afirst radial surface 32 to a second cylindrical surface 34 of greaterdiameter than that of surface 30. A second radial surface 36 connectsthe second cylindrical surface 34 to a third cylindrical surface 38which extends to the planar front face surface 14. The third cylindricalsurface 38 is of greater diameter than the diameter of the secondcylindrical surface 34.

A fourth cylindrical surface 40 is connected to the central cylindricalsurface 30 on an opposite side by means of a third radial surface 42with the fourth cylindrical surface 40 being of greater diameter thanthe diameter of the third cylindrical surface 38. A fourth radialsurface 44 connects the fourth cylindrical surface 40 to a fifthcylindrical surface 46 which is of greater diameter than the diameter offourth cylindrical surface 40. It will be observed that the variouscylindrical surfaces cooperate with their adjacent radial surfaces toprovide annular seats for annular seal members in a manner to bediscussed hereinafter.

FIG. 3 illustrates the manner in which the universal gland 10 is mountedon a housing having a rotary shaft 48 on which a rotary seal 52 ismounted for rotation in engagement with a junction with a stationaryseal 50 of conventional design. It is to be understood that rotary sealmember 52 is connected to the shaft 48 for rotation therewith byconventional means. The stationary seal 50 and the rotary seal 52 havecontacting radial sealing surfaces which operate in a well-known manner.An annular gasket 54 is provided between the first radial surface 32 ofthe gland 10 and a radial end surface 56 of the stationary seal member50 with a second annular gasket 58 being compressed between thestationary seal member 50 and the side of the housing 26 as clearlyshown in FIG. 3. The universal seal gland member 10 holds the sealcomponents 50 and 52 in the illustrated position as a result of thetightening of bolt members 60 extending through apertures 24 which havepreviously been drilled on the proper concentric bolt hole circles 18.

FIG. 4 illustrates the manner in which the universal seal gland 10 cansimilarly be employed with a different housing 126 and a shaft 148 ofless diameter for holding a second type stationary annular seal 150 incontact with a second rotary seal member 152. It will be observed that afirst annular gasket 154 is clamped between the radial surface 32 andthe end surface of the stationary seal member 150 while a second annulargasket 156 is clamped against the side of housing 156 with the sealmembers 150 and 152 being in sealing contact. Thus, it will be seen thatthe universal seal gland provides an effective mounting of thestationary seal member 150 in conjunction with the rotary seal 152,casing 126 and shaft 148.

FIG. 5 illustrates the mounting of the universal seal gland 10 inconjunction with a third housing 226 of a pump or the like having ashaft 248 of a third diameter. In the embodiment of FIG. 5, a thirdstationary seal member 250 is held in contact with a third rotary sealmember 252 with the stationary seal member 250 engaging an outer gasket254 which also engages the third radial surface 42 of the universalgland member 10. The opposite side of stationary seal member 250 isengaged with an inner annular gasket 258 which also engages the end ofthe housing 226 in an obvious manner. Thus, FIG. 5 illustrates themanner in which the universal gland seal can be mounted with a thirdsealing surface in conjunction with a third shaft size. The other radialsurfaces can be similarly engaged with different sized stationary sealmembers.

FIG. 6 illustrates a second embodiment 110 of the universal seal glandin which a centrally positioned cylindrical surface 130 is provided inconjunction with a second cylindrical surface 134, a first radialsurface 132, a second radial surface 136 and a third cylindrical surface138 of reduced axial extent. Additionally, a third radial surface 142provides a connection from the central cylindrical surface 30 to afourth cylindrical surface 140 connected to a fifth cylindrical surface146 of reduced axial extent by a fourth radial surface 144. Stationaryseal member 350 engages a rotary seal member 352 of conventionalconstruction with a second annular gasket 358 being pressed between thefourth radial surface 44 of the gland 110 and the end of a housing 326in conjunction with a shaft 348.

FIG. 7 illustrates the manner in which the second embodiment 110 canalso be associated with a fourth stationary seal member 450 employing asealing ring 454 between it and the gland member. It will be appreciatedthat a similar sealing member of smaller outside diameter could bemounted in the same manner in conjunction with the second cylindricalsurface 134 by a simple reversal of the orientation of the seal gland110.

FIG. 8 illustrates a universal gland having an alternative peripheralconfiguration which could be employed with either of the gland members10 or 110 in which outer cylindrical surface 112 is interrupted byplanar chordal surfaces 113 and 115 to reduce the height of the glandmember for use in housings where clearance is reduced. Also, thealternative construction of FIG. 8 illustrates the employment ofinwardly extending U-slots 117 for receiving mounting bolts for clampingthe gland in position in a well-known manner. Moreover, bolt holeopenings 124 are also providable on any of the concentric rings 118 inthe same manner as discussed with respect to the embodiment of FIG. 1.

Thus, it will be seen that the embodiments of the invention as discussedabove are usable with a wide variety of rotary seal systems anddifferent shaft sizes so as to be usable with a wide variety of devices.Numerous modifications of the disclosed embodiments will undoubtedlyoccur to those of skill in the art, for example, the gland could beformed of metal when the device is to be used in high-temperatureenvironments such as on hot fluid pumps.

Also, the exact array of the cylindrical surfaces can be varied; forexample, the positions of surfaces 38 and 40 could be reversed so thatsurface 38 would occupy the position of surface 40 and vice versa. Ittherefore should be understood that the spirit and scope of theinvention is to be limited solely by the appended claims.

I claim:
 1. The combination of a housing, a rotary shaft mounted forrotation in said housing and extending through an opening in the housingexternally thereof, a rotary seal member attached to the rotary shaftfor rotation therewith, a universal mechanical seal gland mounted onsaid housing coaxially over said rotary shaft for positioning a fixedannular seal against said housing and also against said rotary sealmember, said seal gland comprising an annular body member formed ofplastic and having front and rear parallel planar face surfaces, anaperture extending through said body member concentrically oriented withrespect to a main axis perpendicular to said front and rear parallelplanar face surfaces, said aperture being defined by a plurality ofcoaxial cylindrical surfaces of different diameters with adjacent onesof said cylindrical surfaces being connected by planar sealing surfacesoriented perpendicularly to the axis of said coaxial cylindricalsurfaces.
 2. The seal gland of claim 1 additionally including aplurality of concentric circles formed on said front planar face surfaceand coaxially positioned with respect to said cylindrical surfaces. 3.The seal gland of claim 2 wherein said coaxial cylindrical surfacesinclude a central cylindrical surface of smaller diameter than the othercylindrical surfaces and a second cylindrical surface positionedadjacent said central cylindrical surface, a third cylindrical surfacepositioned adjacent and between said second cylindrical surface and saidfront planar face surface, a fourth cylindrical surface positionedadjacent and between said central cylindrical surface and a fifthcylindrical surface positioned adjacent the rear planar face surface. 4.The seal gland of claim 2 additionally including bolt receivingapertures extending through said body member and bolt means extendingthrough said bolt receiving apertures into said housing for holding saidmechanical seal gland in position thereof.
 5. The seal gland of claim 1wherein said coaxial cylindrical surfaces include a central cylindricalsurface of smaller diameter than the other cylindrical surfaces and asecond cylindrical surface positioned adjacent said central cylindricalsurface, a third cylindrical surface positioned adjacent and betweensaid second cylindrical surface and said front planar face surface, afourth cylindrical surface positioned adjacent and between said centralcylindrical surface and a fifth cylindrical surface positioned adjacentthe rear planar surface.